66655387 has 2 divisors, whose sum is σ = 66655388. Its totient is φ = 66655386.

The previous prime is 66655339. The next prime is 66655409. The reversal of 66655387 is 78355666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66655387 - 2²³ = 58266779 is a prime.

It is a super-2 number, since 2×66655387² = 8885881232239538, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66655327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33327693 + 33327694.

It is an arithmetic number, because the mean of its divisors is an integer number (33327694).

Almost surely, 2^66655387 is an apocalyptic number.

66655387 is a deficient number, since it is larger than the sum of its proper divisors (1).

66655387 is an equidigital number, since it uses as much as digits as its factorization.

66655387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 907200, while the sum is 46.

The square root of 66655387 is about 8164.2750443625. The cubic root of 66655387 is about 405.4572633447.

The spelling of 66655387 in words is "sixty-six million, six hundred fifty-five thousand, three hundred eighty-seven".